Task 5 Research
Principal Investigator(s): Raul I. Cabrera
We mutually agree for Raul I. Cabrera to deliver the following during the period of July 1, 2010 to June 30, 2011 using funds from the Rio Grande Basin Initiative:
- Evaluating rootzone stresses and the role of the root system on rose crop productivity, fertilizer and water use efficiency. This study will characterize the biomass and flower productivity and quality, and physiological performance of rose plants growing on their own roots versus grafted on a rootstock when growing under challenging rootzone stresses, namely fertility (nitrogen), salinity (including boron stress) and alkalinity (varying pH conditions). The experiments will involve a split root system approach that will only stress a portion of the root system, effectively mimicking more closely the nature of rootzone stress under standard commercial conditions.
- Continue evaluating the water and nutrient use of three Texas native street trees (Ulmus crassifolia, Celtis laevigata and Maclura pomifera) infested by the parasitic xylem-tapping leafy mistletoe (Phoradendron spp.). We will monitor water and nutrient use by mistletoes in mature infected trees growing under a range of landscape management conditions. This includes physiological determinations of water relations and nutrient status (stomatal conductance, water potential, chlorophyll, tissue nutrient concentrations) in both the mistletoe and its hosts through a second year. In addition, using container-grown cedar elms (Ulmus crassifolia) manually infected with mistletoe, we will measure, by mass-balance approaches, water and nitrogen fertilizer use by the whole plants in comparison to non-infected (control) plants, both under stressful and optimal management conditions.